export default (function (o, c, d) {
  var LT = 'h:mm A';
  var L = 'MM/DD/YYYY';
  var calendarFormat = {
    lastDay: '[Yesterday at] ' + LT,
    sameDay: '[Today at] ' + LT,
    nextDay: '[Tomorrow at] ' + LT,
    nextWeek: 'dddd [at] ' + LT,
    lastWeek: '[Last] dddd [at] ' + LT,
    sameElse: L
  };
  var proto = c.prototype;

  proto.calendar = function (referenceTime, formats) {
    var format = formats || this.$locale().calendar || calendarFormat;
    var referenceStartOfDay = d(referenceTime || undefined).startOf('d');
    var diff = this.diff(referenceStartOfDay, 'd', true);
    var sameElse = 'sameElse';
    /* eslint-disable no-nested-ternary */

    var retVal =
      diff < -6
        ? sameElse
        : diff < -1
          ? 'lastWeek'
          : diff < 0
            ? 'lastDay'
            : diff < 1
              ? 'sameDay'
              : diff < 2
                ? 'nextDay'
                : diff < 7
                  ? 'nextWeek'
                  : sameElse;
    /* eslint-enable no-nested-ternary */

    var currentFormat = format[retVal] || calendarFormat[retVal];

    if (typeof currentFormat === 'function') {
      return currentFormat.call(this, d());
    }

    return this.format(currentFormat);
  };
});
